APPENDIX A: EDITOR FUNCTIONS AND FORMAT EFFECTORS
A.1 Correspondence between editor functions and format effectors
Table 6 shows on the same line editor functions and format effectors with similar functions. The notation (s), (n) or (n;m) following an abbreviation indicates that the control function is represented by a control sequence with a selective parameter, one numeric parameter, or two numeric parameters. An abbreviation without such a notation indicates that the control function is an element of the CO or C1 set. Format effectors from Standard ECMA-6 are also included. Where there is only one entry on a single line, there is no control function corresponding to the one shown.
| Editor Function | Format Effector |
|---|---|
| CBT (n) | |
| CHA (n) | CR, HPA (n) |
| CHT (n) | HT |
| CNL (n) | NEL, NL |
| CPL (n) | |
| CTC (s) | HTS, TBC (s), VTS |
| CUB (n) | BS |
| CUD (n) | IND, LF, VPR (n) |
| CUF (n) | HPR (n), SP |
| CUP (n;m) | HVP (n;m) |
| CUU (n) | RI |
| CVT (n) | VT |
| DCH (n) | |
| DL (n) | |
| EA (s) | |
| ECH (n) | |
| ED (s) | |
| EF (s) | |
| EL (s) | |
| FNT (n;m) | |
| GSM (n;m) | |
| GSS (n) | |
| HTJ | |
| ICH (n) | |
| IL (n) | |
| JFY (s) | |
| NP (n) | FF |
| PLD | |
| PLU | |
| PP (n) | |
| QUAD (s) | |
| SGR (s) | |
| SPI (n;m) | |
| SD (n) | |
| SL (n) | |
| SR (n) | |
| SSU (s) | |
| SU (n) | |
| TSS (n) | |
| VPA (n) |
TABLE 6: CORRESPONDENCE BETWEEN EDITOR FUNCTIONS AND FORMAT EFFECTORS
A.2 Differences between editor functions and format effectors
The contrast between editor functions and format effectors, together with their interaction with certain modes, is illustrated by the following example of the use of the control functions CURSOR NEXT LINE (CNL) and NEXT LINE (NEL).
In the example it is assumed that the string of capital letters:
A B C D E F
has been entered or received, and that the active position has been moved back
to the letter D, e.g. by-means of CURSOR BACKWARDS (CUB). Starting from this
situation, the following cases are considered.
Case 1: A CURSOR NEXT LINE (CNL) is received. In this case, the active position is moved to the beginning of the next line without affecting the previously received data.
Case 2: The FORMAT EFFECTOR ACTION MODE being set to EXECUTE, a NEXT LINE (NEL) is received. This has the same effect as in case 1).
Case 3: The FORMAT EFFECTOR ACTION MODE being set to STORE and the INSERTION REPLACEMENT MODE to REPLACE, a NEXT LINE (NEL) is received. In this case, the letter D is replaced by NEL. If the data is subsequently forwarded to another device operating with the FORMAT EFFECTOR ACTION MODE being set to EXECUTE, the effect is:
A B C
E F
Case 4: The FORMAT EFFECTOR ACTION MODE being set to STORE and the INSERTION REPLACEMENT MODE to INSERT, a NEXT LINE (NEL) is received. In this case, the NEL is inserted between the letters C and D. If the data is subsequently forwarded to another device operating with the FORMAT EFFECTOR ACTION MODE being set to EXECUTE, the effect is:
A B C
D E F
Format effectors which have been received while the FORMAT EFFECTOR ACTION MODE is set to STORE can be operated upon with editing functions.
For example, the NEL which has been inserted between A B C and D E F in case 4) can be deleted using DELETE CHARACTER (DCH), resulting in the initial situation being restored.
A.3 Composite graphic characters
Because the format effectors can be stored in a receiving device, as opposed to the editor functions which are immediately performed, format effectors rather than editor functions should be used for the construction of composite graphics.
For example, if the symbol ≠ is to be composed using = (EQUALS SIGN) and /
(SOLIDUS), the sequence:
= CUB /
does not produce the desired effect if received by a device which has no overstrike capability. Such a device may, however, process the sequence:
= BS /
in such a way that it is preserved and can be forwarded to a device which can indeed produce the intended composite symbol.